Earth: The Nature of our Planet

At first sight, our atmosphere seems empty. But this layer of air is a habitat for life in its own right, and home to a surprisingly wide variety of creatures – the most conspicuous of which are surely birds. Many seabirds, like the albatross or the Atlantic puffin, spend much of their lives on the wing. This way, they cover enormous distances. The record holder among all bird species is the sooty tern, which can stay in the air for months at end, flying thousands of kilometers. Drinking, feeding and even sleeping: the sooty tern performs all vital activities in flight. Only during the breeding season does this frequent flyer come onto land, where it raises its young in large colonies.

The tectonic plates of our planet are in constant motion. When they collide and grind against each other, earthquakes or tsunamis may result. Paradoxically, the destructive forces below ground are also a source of new life. It begins when plant seeds are transported by the wind to the pristine new islands, germinate and then vegetation takes root. The colonization of new territory is often a matter of chance. When fruit bats migrate to tropical islands, they inadvertently spread plant seeds from one place to the next by means of their excrements; while wind can transport spiders, still clinging to their webs, across vast distances to strange new homes.

It's ironic that we call our planet 'Earth', when two thirds of its surface are covered by water! The oceans, with their fluctuating water temperatures and global currents, also act as a driving force for local weather phenomena and global climate change. In addition, they provide an immense habitat for a countless variety of species. Some of the most important are microscopically small plants and bacteria. Under the right environmental conditions, they can be seen from space in one of nature's most mysterious spectacles, the algal bloom, a sudden mass reproduction of phytoplankton that changes the color of vast bodies of water into a creeping, luminescent, blue-green expanse. A wonderful vision, but as is so often the case in nature – what is good for some is deadly to others.